There is a growing desire in the design of various structures to have structures that can change shape or position without the use of bulky mechanical devices. For example, in mobile platform design, e.g. aircraft, automobiles, trains and ships, to have structures that can change shape or position while the mobile platform is in operation. Such shape or positional changes are often desirable to meet fluctuating aerodynamic needs throughout the duration of the mobile platform's travel. Typically, such dynamic shaping is performed through specific control structures such as flaps, spoilers, ailerons, elevators, rudders, etc. These structures are normally rigid structures that are hinged and pivotally actuated utilizing complex kinematic mechanisms driven by bulky electric or hydraulic actuators. Typically, such kinematic mechanisms and actuators are located either on an exterior surface of the structure or within internal cavities of the structure.
However, it is often desirable to dynamically alter the shape or position of structures that can not internally or externally accommodate such kinematic mechanisms and the actuators that drive them. For example, with present day jet aircraft, structures typically known in the industry as “chevrons” have been used to help in suppressing noise generated by a jet engine. The chevrons have traditionally been fixed (i.e., immovable), triangular, tab-like elements disposed along a trailing edge of a jet engine bypass and/or core nacelles such that they project into, and interact with, the exiting flow streams. Although the chevrons have been shown useful to attenuate noise, since they interact directly with the flow streams generated by the engine, the chevrons also generate drag and loss of thrust. Consequently, it would be desirable to have the chevrons deploy into the flow streams when noise reduction is a concern and then return or move to a non-deployed position when reduction of drag is a concern. However, due to the aerodynamics necessities and extreme operational conditions associated with the engine nacelle and chevrons, kinematic mechanisms and the related actuators that would be needed to deploy the chevrons can not be located on external surfaces of the nacelle and chevrons. Furthermore, neither the nacelle structure nor the chevron structures provide adequate internal space to accommodate such kinematic mechanisms and actuators.
Thus, there exists a need for a system and method for dynamically altering the shape or position of structures, such as mobile platform control structures, without complex kinematic mechanisms or the use of bulky actuators.